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0.207 0.919 0.720 0.052 0.542 0.587 0.024 0.588 0.912 0.323 0.381 0.365 0.867 0.981 0.987
0.465 0.286 0.210 0.381 0.145 0.188 0.852 0.535 0.723 0.047 0.168 0.993 0.567 0.084 0.830
0.037 0.899 0.193 0.756 0.239 0.533 0.197 0.141 0.441 0.563 0.513 0.220 0.684 0.977 0.293
0.907 0.210 0.484 0.054 0.307 0.651 0.603 0.892 0.011 0.186 0.516 0.538 0.547 0.802 0.189
0.876 0.385 0.902 0.724 0.038 0.791 0.592 0.250 0.954 0.799 0.634 0.845 0.455 0.913 0.077
0.649 0.420 0.313 0.099 0.478 0.842 0.654 0.774 0.627 0.038 0.196 0.984 0.331 0.094 0.555
0.142 0.243 0.852 0.742 0.809 0.720 0.126 0.359 0.809 0.200 0.842 0.245 0.063 0.726 0.398
0.879 0.048 0.734 0.605 0.685 0.613 0.529 0.817 0.813 0.746 0.879 0.737 0.227 0.443 0.634
0.765 0.138 0.236 0.948 0.633 0.097 0.354 0.909 0.084 0.871 0.002 0.507 0.567 0.702 0.206
0.143 0.863 0.731 0.555 0.917 0.552 0.249 0.047 0.108 0.256 0.028 0.632 0.723 0.845 0.360
0.137 0.118 0.979 0.319 0.458 0.742 0.205 0.329 0.533 0.852 0.251 0.936 0.065 0.166 0.812
0.223 0.410 0.878 0.946 0.956 0.301 0.297 0.605 0.788 0.196 0.939 0.185 0.396 0.172 0.954
0.735 0.201 0.169 0.265 0.424 0.083 0.162 0.265 0.639 0.761 0.584 0.430 0.826 0.564 0.692
0.349 0.845 0.462 0.843 0.520 0.630 0.735 0.578 0.975 0.411 0.801 0.196 0.232 0.703 0.387
0.229 0.673 0.815 0.986 0.146 0.061 0.774 0.830 0.324 0.339 0.696 0.170 0.998 0.155 0.680
0.133 0.731 0.363 0.723 0.055 0.623 0.016 0.103 0.959 0.307 0.843 0.187 0.307 0.691 0.932
0.262 0.911 0.906 0.743 0.489 0.081 0.745 0.026 0.891 0.638 0.822 0.235 0.539 0.116 0.011
0.336 0.252 0.700 0.009 0.533 0.159 0.602 0.516 0.809 0.496 0.703 0.374 0.708 0.376 0.791
0.958 0.075 0.069 0.337 0.659 0.506 0.889 0.890 0.546 0.419 0.141 0.971 0.928 0.604 0.785
0.521 0.159 0.308 0.293 0.134 0.235 0.910 0.669 0.984 0.688 0.107 0.738 0.705 0.496 0.661
0.447 0.196 0.023 0.176 0.600 0.977 0.889 0.968 0.016 0.064 0.016 0.576 0.945 0.597 0.314
0.166 0.171 0.881 0.158 0.583 0.320 0.332 0.745 0.158 0.084 0.558 0.332 0.247 0.785 0.630
0.800 0.209 0.065 0.599 0.900 0.431 0.760 0.196 0.868 0.188 0.483 0.843 0.739 0.699 0.106
0.669 0.223 0.705 0.040 0.307 0.699 0.575 0.336 0.049 0.791 0.435 0.768 0.911 0.753 0.052
0.195 0.881 0.862 0.247 0.163 0.970 0.851 0.336 0.746 0.001 0.514 0.635 0.064 0.781 0.350
0.306 0.951 0.141 0.778 0.541 0.668 0.651 0.631 0.960 0.498 0.095 0.339 0.543 0.848 0.153
0.975 0.401 0.636 0.675 0.648 0.031 0.107 0.036 0.461 0.809 0.919 0.145 0.435 0.620 0.333
0.201 0.088 0.019 0.301 0.838 0.287 0.214 0.965 0.189 0.530 0.627 0.918 0.364 0.690 0.709
0.985 0.769 0.866 0.181 0.803 0.845 0.571 0.791 0.367 0.163 0.372 0.254 0.172 0.541 0.340
0.274 0.264 0.770 0.634 0.736 0.429 0.132 0.706 0.652 0.466 0.427 0.377 0.119 0.075 0.942
0.668 0.591 0.949 0.904 0.819 0.087 0.688 0.195 0.159 0.976 0.155 0.320 0.314 0.894 0.659
0.045 0.253 0.730 0.410 0.521 0.696 0.504 0.235 0.569 0.935 0.621 0.215 0.202 0.419 0.178
0.004 0.479 0.726 0.722 0.616 0.536 0.880 0.859 0.334 0.994 0.088 0.845 0.528 0.513 0.359
0.896 0.401 0.709 0.741 0.017 0.246 0.758 0.063 0.755 0.133 0.574 0.829 0.751 0.908 0.228
0.081 0.466 0.824 0.237 0.461 0.214 0.669 0.084 0.948 0.468 0.164 0.785 0.822 0.200 0.991
0.109 0.986 0.673 0.674 0.805 0.388 0.900 0.342 0.674 0.403 0.250 0.113 0.924 0.851 0.860
0.518 0.032 0.881 0.880 0.989 0.917 0.497 0.268 0.121 0.474 0.441 0.998 0.857 0.201 0.649
PASCAL
FERMAT
Investments2
STATISTICAL REVIEW
Overview of Applied Statistics for Financial Analysis
Antonio J. Macias
Antonio Macias
Three-step approach Capital Allocation*
Investments3
Parameters: Estimate
• expected returns
• standard deviations of returns, and
• correlations between assets
One-fund theorem: Find optimal risky portfolio or tangency portfolio
• stocks
• bonds
Two-fund theorem:According to your risk aversion, combine
• optimal risky portfolio with
• the risk-free asset (T-bills) rf
p
E(rp)
p
1-
2-
3-
* This is a very important summary slide of
what we will study in the Investment I course
rf
p
E(rp)
rrisky-assets
1. Stock trading “How-to?”
2. Risk and Return “What to measure”
Quantify parameters
3. Optimal asset allocation “Where? / Which assets? /
How much?”
4. Asset Pricing Models “How to asses?”
5. Security Valuation “Why this asset?” Later
HWSTG
Ch. 1 & 2
Antonio Macias
Learning objectives What is a random variable? How to calculate means and standard deviations? What is covariance and how to measure it?
What is correlation?
What is the mean and standard deviation of a portfolio of individual returns?
You saw these concepts in Ch. 13 of Block-Hirt, in the required course: FINA 30153
review if needed
1-Useful summary formulas2- In-Class Example
Investments4
Antonio Macias
Definition of Investment
“Current commitment of money or other resources in the expectation of reaping future benefits”
Cost – Benefit tradeoff
Stock Return:
What we pay vs. what we get
Investments5
Antonio Macias
Definition
Net return
Pt : price today
Pt+1 : price tomorrow
Dt+1 : dividend tomorrow
Investments6
1111
t
ttt
P
DPr
Antonio Macias
Example
Buy share at $50;
At end of year it is worth $55, and
Pays $2 dividend
Gross Return = (2+55)/50 =1 .14 =114%
Net Return = (2+55)/50 –1 =0 .14 =14%
Investments7
Antonio Macias
Net return
Income yield : cash payout
Capital gain/loss : change in security price
Investments8
gain/loss capitalyield income
1
11
111
t
tt
t
t
t
ttt
P
PP
P
D
P
DPr
Antonio Macias
Example (contd..)
Buy share at $50
At end of year it is worth $55, and
Pays $2 dividend
Income yield = $2/$50= 4%
Capital gain = ($55-$50)/$50=10%
Investments9
Antonio Macias
Statistics: Basics
Random Variable
Uncertain outcomes
Probability Distribution (Histogram)
List of values with their associated probability
Continuous versus Discrete
Example: Roll of a die
Investments10
X 1 2 3 4 5 6
Prob 1/6 1/6 1/6 1/6 1/6 1/6
Antonio Macias
Descriptive Statistics
Mean : Average value
Variance (standard deviation) : dispersion
Normal Distribution
Investments11
mean
s.d. s.d.
Antonio Macias
Expected (Mean) return
Investments12
where
rs : return if a state occurs
ps : probability of a state
where
rt : return in period t
pt : probability of period t is 1/T
S
s
ssrpr1
]~E[T
t
trT
r1
1]~E[
Antonio Macias
Example – mean
Mean =
=
Does not have to be one of the outcomes
Investments13
X 1 2 3 4 5 6
Prob 1/6 1/6 1/6 1/6 1/6 1/6
Antonio Macias
Mean =1/6*1 + 1/6*2 + 1/6*3 + 1/6*4 + 1/6*5 + 1/6*6
=3.5
Does not have to be one of the outcomes
Investments14
X 1 2 3 4 5 6
Prob 1/6 1/6 1/6 1/6 1/6 1/6
Example – mean
Antonio Macias
Variance
or
Shortcut:
Investments15
T
t
t )r(rT
r1
2]~E[1
]~V[
S
s
ss )r(rpr1
2]~E[]~V[
T
t
t rrT
r1
22]~E[
1]~V[
Antonio Macias
Standard deviation
Standard deviation is the square root of variance
Investments16
]~V[]~[SD rr
Antonio Macias
Example – variance
Variance
=
=
Investments17
X 1 2 3 4 5 6
Prob 1/6 1/6 1/6 1/6 1/6 1/6S
s
ss )r(rpr1
2]~E[]~V[
Antonio Macias
Variance =1/6*(1-3.5)^2 + 1/6*(2 -3.5)^2 + 1/6*(3 -3.5)^2 +
1/6*(4 -3.5)^2 + 1/6*(5 -3.5)^2 + 1/6*(6 -3.5)^2
=2.92
Investments18
X 1 2 3 4 5 6
Prob 1/6 1/6 1/6 1/6 1/6 1/6S
s
ss )r(rpr1
2]~E[]~V[
Example – variance
Antonio Macias
Example – variance (w/shortcut)
Variance
=
=
=
Investments19
X 1 2 3 4 5 6
Prob 1/6 1/6 1/6 1/6 1/6 1/6
T
t
t rrT
r1
22]~E[
1]~V[
Antonio Macias
Variance
=[1/6*1^2 + 1/6*2^2 + 1/6*3^2 + 1/6*4^2 + 1/6*5^2 + 1/6*6^2] – 3.5^2
=15.17-12.25
=2.92
Investments20
X 1 2 3 4 5 6
Prob 1/6 1/6 1/6 1/6 1/6 1/6
T
t
t rrT
r1
22]~E[
1]~V[
Example – variance (w/shortcut)
Antonio Macias
Example – standard deviation
Standard deviation
=
=
Investments21
X 1 2 3 4 5 6
Prob 1/6 1/6 1/6 1/6 1/6 1/6
Antonio Macias
Standard deviation
= 2.92
=1.71
Investments22
X 1 2 3 4 5 6
Prob 1/6 1/6 1/6 1/6 1/6 1/6
Example – standard deviation
Antonio Macias
Covariance of returns
Measure of movement in tandem
Correlation
Investments23
S
s
sss
S
s
sss
rrrrp
)r)(rr(rprr
1
21,2,1
1
2,21,121
]~E[]~E[
]~E[]~E[]~,~C[
]~[SD]~[SD
]~,~[C
21
2112
rr
rr
Antonio Macias
Correlations
Investments24
Correlation=-0.9
-2
-1
0
1
2
-2 -1 0 1 2
Correlation=+0.9
-2
-1
0
1
2
-2 -1 0 1 2
Correlation=0.0
-2
-1
0
1
2
-2 -1 0 1 2
Antonio Macias
Covariance of returns (contd..)
Another way
By the way
Correlation lies between –1.0 and 1.0
Investments25
]~[SD]~[SD]~,~[C 211221 rrrr
]~[V]~,~[C 111 rrr
Antonio Macias
Notational convention (confusion!)
Mean E[r] or or
Variance V[r] or 2
Standard deviation SD[r] or
Covariance of r1 and r2
C[r1 , r2] or 12
Correlation of r1 and r2
or 12
Investments26
211212
r
Antonio Macias
Larger example
Two stocks, 3 states of the world
Investments27
State 1 State 2 State 3
Probability 0.33 0.33 0.33
Stock A returns 15% 5% -10%
Stock B returns 10% 10% -5%
Antonio Macias
Example - means
Mean returns
Investments28
B
A
r
r
Antonio Macias
Mean returns
Investments29
%0.5%)5(3
1%10
3
1%10
3
1
%33.3%)10(3
1%5
3
1%15
3
1
B
A
r
r
Example - means
Antonio Macias
Example – Variances
Variances
Important point to remember!
Variances are not expressed in percentages
Variance of stock A is NOT x.xx%
Note that the variance has squared units = %^2!
Investments30
2
2
B
A
Antonio Macias
Variances
Important point to remember!
Variances are not expressed in percentages
Variance of stock A is NOT 1.06%
Note that the variance has squared units = %^2!
Investments
005.0%5%53
1%5%10
3
1%5%10
3
1
0106.0%3.3%103
1%3.3%5
3
1%3.3%15
3
1
2222
2222
B
A
Example – Variances
Antonio Macias
Example – Standard deviations
Standard deviations
Standard deviations are percentages
Investments32
B
A
Antonio Macias
Standard deviations
Standard deviations are percentages
Investments33
%1.7005.0
%3.100106.0
B
A
Example – Standard deviations
Antonio Macias
Example - Correlation
Covariance
Correlation
Investments34
AB
BA
ABAB
S
s
sss
S
s
sss
rrrrp
)r)(rr(rprr
1
21,2,1
1
2,21,121
]~E[]~E[
]~E[]~E[]~,~C[
Antonio Macias
Covariance
Correlation
Investments35
0067.0
%5%5%3.3%103
1
%5%10%3.3%53
1%5%10%3.3%15
3
1AB
92.00707.01027.0
0067.0
BA
ABAB
Example - Correlation
Antonio Macias
Mean and variance of sumof returns
Mean of sum is the sum of individual means
Variance of sum is NOT the sum of individual variances
Similarly, standard deviation of sum not the sum of individual standard deviations
Investments36
]~,~[C2]~[V]~[V]~~[V 212121 rrrrrr
]~[E]~[E]~~[E 2121 rrrr
Antonio Macias
Mean and variance of average of returns
Mean of average is the average of individual means
Variance of average is NOT the average of individual variances
Investments37
]~,~[C2]~[V]~[V4
1
2
~~V 2121
21 rrrrrr
]~[E]~[E2
1
2
~~E 21
21 rrrr
Antonio Macias
Example
Equal weighted portfolio of same stocks as in previous example
Estimate mean and standard deviation1. As if the portfolio were a single financial assets (for
ex. An ETF)2. Using the portfolio formulas based on the weights of
the individual assets contained in the portfolio
Investments38
State 1 State 2 State 3
Probability 0.33 0.33 0.33
Stock A returns 15% 5% -10%
Stock B returns 10% 10% -5%
Portfolio returns 12.5% 7.5% -7.5%
Antonio Macias
1- Example – portfolio mean and variance:Estimated as if portfolio were a single financial asset (imagine an ETF share)
Mean
Variance
Investments39
2BA
P
rr
r
2
P
n
i
ii RERp1
22))((σ
n
i
ii RpRE1
)(
Antonio Macias
Mean
Variance
Investments40
%2.42%5%33.32
%2.4%)5.7(3
1%5.7
3
1%5.12
3
1
BA
P
rr
r
0072.0
%2.4%5.73
1
%2.4%5.73
1%2.4%5.12
3
1
2
222
P
1- Example – portfolio mean and varianceEstimated as if portfolio were a single financial asset (imagine an ETF share)
Antonio Macias
Mean
Variance
Investments41
2- Example – portfolio mean and variance using weights of assets in portfolio
)()(1
j
m
j
jp REwRE
ijj
m
ji
iwwVariance1,
2
Antonio Macias
Mean
Mean with 2 assets in the portfolio:
Investments42
2-Example – portfolio mean using weights of assets in portfolio
)()(1
j
m
j
jp REwRE
)()()( 2211 REwREwRE p
Antonio Macias
Variance
Variance with m=2 assets in the portfolio:
Investments43
2-Example – portfolio variance using weights of assets in portfolio
ijj
m
ji
iwwVariance1,
2
122211
2
2
2
2
2
1
2
1
1221
2
2
2
2
2
1
2
1
2222211212211111
2
))((2
2
wwww
wwww
wwwwwwwwVariance
Where 12 is the covariance between asset 1 and 2
And 12 is the correlation between asset 1 and 2
Antonio Macias
2-Example – portfolio standard deviation:based on 2 assets with weight_A = weight_B = 1/2
Standard deviation
Alternatively to first estimation method, we could have used portfolio formulas (2nd
method)*
* It is sometimes easier to apply the more general formula as if we are estimating the std. deviation of a single asset (in this case, the portfolio0, since it is more general
Investments44
2BA
P
ABBA
ABBAP
24
1
2
1*
2
1*2
2
1
2
1
22
2
2
2
2
2
ijj
m
ji
iwwVariance1,
2
Antonio Macias
Standard deviation
Using 2nd method based on portfolio formulas
Investments45
2
%5.80072.0
BA
P
00725.0
0.0067*20.0050.01064
1
24
1 222
ABBAP
Example – portfolio standard deviation
Estimated based on 1st
method as if portfolio
were a single financial
asset
ijj
m
ji
iwwVariance1,
2
Antonio Macias
Investments46
Suppose you have predicted the following returns for stocks C and T in three possible states of nature. What are the expected returns, E[r]? And the standard deviations, ?
State Probability C T .Boom 0.3 0.15 0.25Normal 0.5 0.10 0.20Recession ??? 0.02 0.01
E[rC]= C=E[rT]= T=
What would be the portfolio return, E[rportfolio], and its standard deviation, portfolio, if the weights of the individual assets are:wC = 0.4 and wT = 0.6
In Class Example – Individual and Portfolio returns and standard deviation
Antonio Macias
Investments47
Summary of Useful Formulas:
)()(1
i
N
i
ip rEwrE
ijj
N
j
i
N
i
wwVariance11
2
ji
ij
ijijrhojincorrelatio ),(
s
M
s
si rprE1
)(
2
1
2 ])[(* i
M
s
ss rErp
1111
t
ttt
P
DPr
VarianceDevStd 2..
Stock Return
Portfolio levelIndividual asset level
Where s: state of nature; p: probability of state s; M: number of states of nature;
i: asset i; j: asset j; N: number of assets in portfolio
Antonio Macias
Investments48
1. Expected Value of x:
where x is the random variable, and pi is the probability of state i.
2.A. Expected return of a Portfolio, given probabilities for n different states of nature and the return, Ri for each state of nature
(“branch”)
3. Variance of expected observations:
where x is the random variable, and pi is the probability of state i.
4. Portfolio estimations (given all the j assets included in the portfolio)
4.A Mean-return of a Portfolio:
4.B Variance of a Portfolio
4.C Correlation coefficient between two assets:
Where: wi is the weight on asset i with a total of m assets in the portfolio.
ij is the covariance between asset i and j
ij is the correlation coefficient between asset i and j
5. Covariance of expected Observations:
where XAi, X Bi are the values of random variables
A and B in state i. p(si) is the probability of state i.
Various Useful detailed Formulas
i
N
i
i pxxE1
][
i
n
i
i RpRE1
)(
i
N
i
i pxEx *])[( 2
1
2
)()(1
j
m
j
jp REwREijj
m
ji
iwwVariance1,
2
:
ji
ij
ijijrho
states. Nfor
])[])([()( ...
])[])([()(
])[])([()(),(C
222
111
BBNAANN
BBAA
BBAABA
XEXXEXsp
XEXXEXsp
XEXXEXspXXOV
Note that the letter you use for each index and for the total number of elements
for each summation can change, as long as you are consistent with your
problem at hand. The nomenclature is just and aid to solve the problems.
Antonio Macias
Investments49
1-Summation, or Sigma, Notation
http://www.math.montana.edu/frankw/ccp/general/sigma/learn.htm
Great place to find an introduction to the topic, with many
Applied examples to assess your understanding
2- Series (mathematics)
http://en.wikipedia.org/wiki/Series_(mathematics)
From Wikipedia, the free encyclopedia
A series is the sum of the terms of a sequence. Finite sequences and series have defined first and last
terms, whereas infinite sequences and series continue indefinitely. [1]
In mathematics, given an infinite sequence of numbers { an }, a series is informally the result of
adding all those terms together: a1 + a2 + a3 + · · ·. These can be written more compactly using
the summation symbol ∑. An example is the famous series from Zeno's dichotomy
The terms of the series are often produced according to a certain rule, such as by a formula, or by
an algorithm. As there are an infinite number of terms, this notion is often called an infinite series.
Unlike finite summations, infinite series need tools from mathematical analysis to be fully understood
and manipulated. In addition to their ubiquity in mathematics, infinite series are also widely used in
other quantitative disciplines such as physics and computer science.
Appendix: Useful Resources about Summations (Series)
:
Antonio Macias
Investments50
Statistical and Probability Overview
Key Concepts for Investment Management: What is a random variable? How to calculate means and standard deviation? What is covariance and how to measure it? What is correlation?
What is the mean and standard deviation of a portfolio of individual returns?
Skim Chapter 5 for application in Finance (we will see more later)
Online resources: http://www.uidaho.edu/stat/scc/review1.htm http://homepages.wmich.edu/~bwagner/StatReview/index.html http://hspm.sph.sc.edu/COURSES/J716/a01/stat.html
Antonio Macias
Three-step approach Capital Allocation*
Investments51
Parameters: Estimate
• expected returns
• standard deviations of returns, and
• correlations between assets
One-fund theorem: Find optimal risky portfolio or tangency portfolio
• stocks
• bonds
Two-fund theorem:According to your risk aversion, combine
• optimal risky portfolio with
• the risk-free asset (T-bills) rf
p
E(rp)
p
1-
2-
3-
* This is a very important summary slide of
what we will study in the Investment I course
rf
p
E(rp)
rrisky-assets
1. Stock trading “How-to?”
2. Risk and Return “What to measure”
Quantify parameters
3. Optimal asset allocation “Where? / Which assets? /
How much?”
4. Asset Pricing Models “How to asses?”
5. Security Valuation “Why this asset?” Later
HWSTG
Ch. 1-3
Ch. 6
Ch. 5
• Ch. 7&on
• *HW7
DCF